Embossing mill registration locking device



Dec. 20, 11966 H. M. LEWIS 3,292,403

' EMBOSSING MILL REGISTRATION LOCKING DEVICE Original Filed Oct. 22,1962 4 Sheets-Sheet 1 {6W 190 9 aid Qua ATTORNEYS Dec. 20, 1966 H. M.LEWIS 3,292,403

EMBOSSING MILL REGISTRATION LOCKING DEVICE Original Filed Oct. 22, 19624 Sheets-Sheet 2 NW EATOR ATTO R'YFKS Dec. 20, 1966 H. M. LEWIS 3,

EMBOSSING MILL REGISTRATION LOCKING DEVICE Original Filed Oct. 22, 1962var- 4.

4 Sheets-Sheet 3 ATTORNEYS Dec. 20, 1966 H. M. LEWIS 3,

EMBOSSING MILL REGISTRATION LOCKING DEVICE Origihal Filed Oct. 22, 19624 Sheets-Sheet 4 INVENTOR BY gww 9M aw ATTORNEY United States Patent 5Claims. (Cl. 72-81) This application is a division of my copendingapplication Serial No. 231,975, filed Oct. 22, 1962, now abancloned, andthe present invention relates to apparatus for making embossing rolls,particularly to the making of female embossing rolls by engraving acylinder with a cylindrical mill whose axis extends parallel to the axisof the cylinder and which has an axial length a number of times lessthan the axial length of the cylinder being engraved thereby.

As the term is used in the .art mill refers to a small cylinder, i.e., acylinder which is short in axial length, and usually lesser in diameter,than the cylinder onto which its pattern is imposed. The design orpattern on the cylindrical surface of the mill is in relief so as tocause the pattern which is thereby engraved onto the cylinder to be inintaglio or recess. In other words, the mill is a small male roll, andthe large cylinder engraved thereby becomes a female embossing roll.

In the past, large cylinders have been embossed by small mills, byrotating the cylinder, after it has been coated with an etching resist,in contact under extremely heavy pressure with the mill, side steppingthe mill one contiguous strip at a time until the full face of thecylinder has its resist removed in certain areas by the protrusions onthe mill so as to leave exposed metal areas on the cylinder. Thecylinder was then etched in an acid 'bath to eat away the metal of theexposed areas to a desired depth. Recoating with resist and re-runningof the cylinder and mill in greater pressure contact, followed by anetching was effected the necessary number of times to obtain the desireddepth of the pattern in the resultant female embossing roll.

One of the problems with the prior art procedures just described, isthat a tremendous amount of pressure on the mill, during the engravingthereby of the successive circumferential strips of the cylinder, wasfound to be essential to maintain traction and registration, i.e., toprevent slippage of the mill relative to the cylinder, under anycircumstance. This is particularly true of the prior art when a fine orshallow pattern is to be engraved onto a cylinder by a short mill orwhen the cylinder is initially a fully hardened tool steel roll, i.e.,hardened substantially its full depth, as opposed to a metal cylinderwhich is substantially softer than the hardened mill. Since the mill inthe prior art procedures above described has been held, as bestpossible, in registration with the rotating cylinder mainly because ofhuge pressures applied between the mill and cylinder, there was alwaysthe chance of traction not being held but slippage resulting, even whenthe cylinder was relatively softer than the mill.

In many instances, there are required embossing rolls that willwithstand the exceptional pressures necessary between two matedembossing rolls during operation thereof to emboss metallic strips orsheets. If the metal being embossed is uneven or irregular in thickness,the embossing rolls as made in accordance with the prior art practicesabove described, and as described in the Sunderhauf et al. Patent2,662,002, will not necessarily withstand the shocks or other forcesproduced thereon. This disadvantage is due to the lack of a sufficienthardening depth of the embossing rolls. In other words, because suchprocedures require engraving the potential female embossing roll whileit is relatively soft, then hardening thereof afterwards can only bedone to effect a case hardening, as opposed to full depth hardening,because the latter may cause undesirable warpage or distortion due tothe radial expansion and contraction incident to full depth furnacehardening for example. The only afterhardening treatment found to bepractical, economical, and satisfactory in the Sunderhauf et al.procedures indicated above, is the 'well known flame hardening procedurewhereby the engraved female embossing roll becomes hard only in theregions of its outer surface or skin, commonly known as case hardening.Because it is desirable for many known reasons to have the mating maleembossing roll to be of not only the same substantial hardness as thefemale embossing roll, but also of the same type of hardness and steel,the male embossing roll of the Sunderhauf process is also only a casehardened steel.

In order to meet the demands for harder embossing rolls, i.e., ones thatwill not crush or otherwise be damaged during their operation ofembossing metal sheets or strips, several procedures have been effectedto allow the embossing rolls to be pre-hardened to any desired depth;for example as fully described and claimed in the Nelson Patent No.3,048,512, and the Di Leo et a1. application entitled Engraving Millsand Making Embossing Rolls Therefrom, Serial No. 206,211, filed June 29,1962, now Patent No. 3,214,310. In the Nelson patent just referred to,the first made embossing roll can \be pre-hardened to full depth beforebeing engraved because the master pattern roller, which causes thedesired engraving of the potential female embossing roll,

is co-extensive with that roll, and can accordingly be positively drivenby rotation of the roll during the engraving procedure without anyproblem. For example, the shafts of the coextensive master patternroller and the female embossing roll being engraved thereby can bedirectly geared together so as to maintain consistent registration andtraction between the pattern roller and female embossing roll to preventany possibility of slippage therebetween. This gearing is possiblebecause of the coextensiveness of the pattern roller and embossing rolland their respective shafts or journals, but positively rotating a millin response to rotation of a cylinder in a situation where the mill mustbe side stepped a number of times in order to fully engrave the desiredpattern area on the cylinder poses many problems unobvious of solution,which the present invention overcomes.

In the above mentioned Di Leo et .21. application,

positive rotation of the mill in response to rotation of the cylinderbeing engraved thereby, is effected by initially causing conicallypointed teeth or snags to protrude from the cylindrical surfaces at eachend of the mill. These cooperate with relatively soft rings that aretemporarily secured to the ends of the cylinder to be engraved, makingapertures whereby the mill and cylinder are effectively geared together.This type of operation is fully satisfactory for full depth pre-hardenedembossing rolls, but is limited to situations Where the pattern area ofthe embossing roll is coextensive to the pattern area on the mill. Thisdisadvantage is overcome by the present invention.

It is therefore a primary object of this invention to provide apparatusfor engraving an embossing roll, by a mill which is a number of timesshorter than the embossing roll, while effecting a positive rotationaldrive of the mill during rotation of the cylinder being engravedthereby, and including a flexible shaft means for driving the mill, thusallowing side stepping of the mill without 3 changing the relativeangular positions of the mill and cylinder.

Another object of this invention in conjunction with theforegoing objectis to effect locking of the mill drive relative to the cylinder orpotential roll drive whereby traction and consistent registrationtherebetween during engraving of the cylinder by the mill is positivelymaintained.

A further object in connection with the above objects to effect saidlocking is the provision of gear driving the mill in synchronism withthe cylinder and side setting the mill without possibility of changingthe relative angular positions of the mill and cylinder.

Other objects and advantages of this application will become apparent tothose of ordinary skill in the art upon, reading the appended claims andthe followingdetailed description of an embodiment of the invention, inconjunction with the drawings, wherein:

' FIGURE 1 is a front elevational view of the apparatus,

FIGURE 2 is an enlarged detailed view of a portion, partially incross-section, of the right end of the front of FIGURE 1,

FIGURE 3 is a right end view'of FIGURE 2,

FIGURE 4 is a front elevational view, partially in cross-section, of apart of the mill holder of'FIGURE 1,

FIGURE 5 is a right end elevational view of FIG- URE 4 with parts brokenaway, and

FIGURE 6 is a right end view of FIGURE 1.

The novel apparatus according to this invention may be appreciatedgenerally [from the FIGURE 1 front elevat-ional view. The cylinder to bemade into a female embossing roll is designated 10. Though not required,the cylinder is shown as having its shafts or journals of steppedreduced diameter, with the central reduction 12 at each end beingdisposed on a bearing or .pillow block 14. To accommodate differentshaft diameters on different size cylinders 10, each pillow block 14 maycontain a diameter adapter insert 16. It will be understood that theshafts of cylinder rest in pillow blocks 14 on inserts 16 so that thecylinder may be rotated about its longitudinal axis.

At the left end of FIGURE 1, the smallest diameter portion 18 of theshaft of cylinder 10 is grasped as by any standard type of chuck 20 theaxle of which is rotatably supported in the bearing stand 22 and whichfurther connects to the bull or driving 'gear 24. Pillow blocks 14 andstand 22 are secured to the frame 26 of the machine, which includes amotor(not shown), preferably an electrical motor, and further drivingmeans coupled to gear 24 for rotating cylinder 10 at a desired speed.Preferably, also, there are .pushbutton switches or the like to effectstart and stop, as well as jog and reverse" as desired.

At the right hand end of FIGURE 1 the smallest shaft reduction or shank28 of the cylinder is chucked, as shown in greater detail in FIGURE 2,by the main drive chuck 30 internally of which is disposed a taperedbushing 32 secured thereto and to shaft 28 by the pressure effected byscrews -34. Bushing 32 is of the split ring type, with, for example, a$5 inch saw cut or the like, so that it may be drawn tightly againstshaft 28 by tightening of screws 34. These screws engage the main chuck3 0 also,-so any rotation of shaft 28 causes chuck 30 to rotate. Chuck30 and a drive plate 36 are interconnected by a. drive pin 38 whichincludes a transversely extending pin or key 40 which is slidable in aslot 42 disposed in an emboss on the main chuck 30. The tapered end ofdrive .pin 38 extends into a slot in the drive plate 36, which issecured as by key 44 to a spindle or rotatable shaft 46. This shaft alsoextends leftwardly inside a steel bushing 48 in the main chuck to effectcentering of the chuck and cylinder. shoulders against bushing 48 toeffect a desired spacing between chuck 30 and drive plate 36 wherebyaxial movement of cylinder shank 28 is prevented. In a right- Shaft 46also Ward direction, shaft 46 is rotated on bearings 50 at one end of abearing box 51 secured to bracket 52, and on like bearings at the otherend of that box. Bracket 52 has an underneath side slot which engagesthe longitudinal vertically extending bar or key 54 which is fixedlysecured to the main bracket 56. By virtue of bracket base 55 v 'beingaflixedly slidable in way 57 (FIGURE 6) in the bed or frame 26 axiallyof the cylinder, bracket 56 is movable leftwardly and ri-ghtwardly (asviewed in FIG- URES 1 and 2) to allow proper mounting of chuck 30 onshank 28 and spindle 46. The vertical position of the bearing bracket 52along key 54 may be accurately adjusted by use of adjustable screw pins58 against abutment 60 that fixedly protrude from brackets 52. Screws 62extend through four respective slots in bracket 52 for securing thatbracket to the main bracket 56, in the correctly adjusted position.

Drive plate 36 is secured to the main spur driving gear I 64 not only bykey 44, but also by four hub screws 66 disposed 90 apart around an axleor shaft 46. Accordingly, as the cylinder shaft 28 turns, so turns themain driving gear 64. This gear in turn .meshes with an idler gear 68,which meshes with an upper drive gear 70.

Briefly, as will be further appreciated from FIGURE 1, rotation of gear70 causes long shaft 72, flexible coupling 74, short shaft 76, andmeshed spur gears 77 and 79" to rotate cylindrical mill 82 against thecylindrical surface of cylinder 10, in a positive driving manner.

In more detail, as is apparent from FIGURE 2 (see also FIGURE 6), shaft72 is splined on diametrically opposing sides to receive respectivebiased keys 75. As indicated, these keys are retained in a housing 76with a pair of springs 78 for each key 75 being effective to push thekey inwardly. There is just enough pressure effected and maintained byjam nuts 80 to allow shaft 72 to move longitudinally of the keys 75. Inother words, the keys may slide in the splines of shaft 72 as that shaftis moved axially in a manner later described. In order to cause retainer76, and consequently keys 75 and shaft 72 to rotate in response torotation of gear 70, a key chuck 82 is employed in conjunction with asleeve 84 that sur- 1 rounds shaft 72. Chuck 82 extends internally ofkey retainer 76 on opposite sides of keys 75 to hold the outer parts ofthe keys vertical, and is fixedly secured to retainer 76 by means notshown, such as by bolts. Sleeve 84, which may be seamless tubing, iscaused to rotate with chuck 82 by use of clamping plugs 86 each of whichincludes two matingly threaded parts extending inwardly from oppositesides of the chuck with arcuate cutouts tightly engaging and clampingthe sleeve to the chuck. Sleeve 84, in turn, contains a keyway as doesgear 70 into which a key 88 is disposed. Accordingly, rotation of gear70 causes sleeve 86 to rotate, and due to clamping by plugs 86, chuck 82in turn rotates and turns the key retainer 86 and its keys 75, elfectingrotation of shaft 72, while at the same time allowing for the lengthwiseadjustability of shaft 72 relative to keys 75 and sleeve 84.

To maintain the proper height of shaft 72 and sleeve 84, the sleeve ismounted in bearings 90 which are re tained in a bearing box 92. As forthe lower bearing box 52, the upper bearing box is'fixedly disposed on abracket 94 which in turn is secured by screws 96 extending throughrespective slots into the main bracket 56, after being adjusted to theproper height along key 54 by adjusting pins 98 operating againstprotruding abutement 100. In order to allow for adjustability in sizesof gears that may be employed to accommodate different size mill andembossing roll diameters, and to effect the desired ratio of angularrotation therebetween to cause equal peri pheral speeds of the mill androll, idler gear 68 is meshed to an adjustably positionable bracket 104.This bracket,

as is apparent from FIGURES 3 and 6 with its mounting slots 106 ismounted on main bracket 56 by bolts 108 in the vertically extendingslots 110 of a rearward projection of the main bracket 56.

Reference is now made to FIGURES 4 and 5. In considering the couplingbetween shaft 76 and mill 82, it will be noted that the left end ofshaft 76 has a reduced diameter portion 118 disposed internally of abushing 112 that is secured to the gear housing 114 by lock screws .116.The reduced diameter portion 118 of shaft 76 contains a keyway, as doesgear 77, with which cooperates key 120. Gears 77 and 79 are illustratedas having these gears being a 1:1 diameter ratio, and the latter iskeyed, as by key 122, to the extended shaft portion 124 of the right endjournal of mill 82, with bushing 126 being grippingly disposedtherebetween. The larger diameter portions 128 on opposite ends of themill shaft are disposed in slots 130 in respective end brackets 132 and134. Bracket 132 has secured to it the previously mentioned gear housing114, as by four bolts 136 through the respective slots in housing 114which allow for vertical adjustment of the housing and gearing apparatuscarried thereby. Spacer 138 is preferably disposed between bracket 132and gear 77 to effect the desired horizontal disposition of the gearrelative to gear 79, which may also be spaced from the bracket as byspacer 140. The right-angling, outwardly extending, upper end 142 ofbracket 132 includes a vertically disposed aperture that carries a holdpin 144 which presses against the adjustable housing 114. This pin 144has a rounded head against which cooperates the conical end of a screwthreaded stud 146 for adjusting the vertical position of pin 144 andconsequently of gear housing 114.

Pins 148, which extend through apertures near the lower end of each ofthe mill shaft brackets 132 and 134, hold the mill rotatably securedtherein, hubs 150 cooperating with these brackets to prevent lateralmovement of the mill 82.

Brackets 132 and 134, at their upper ends extend at right anglesoutwardly and engage at one side in a dovetailing manner the lowerportion of a mill head holder 152, as shown in FIGURE 5 for bracket arm142. At the other side, these bracket arms engage a retaining gib 154,which with its wedge shape cooperates via four threaded screws 156 toretain the mill brackets 132 and 134 securely in the holder 152. Headholder 152 has secured into each of its front and rear sides respectivetrunnions 158 on the protruding heads of which rockably rests mill head160 via its arcuately grooved, depending arms 162. These arms aresecured around trunnions 158 by lower brackets 164, which have anarcuate groove fitting the trunnion, screws 166 being utilized to holdparts 162 and 164 fixed together about trunnions 158.

However, before screws 166 are tightened, the lower plate or holder 152is properly positioned relative to the horizontal so that mill 82 willin turn have its cylindrical surface absolutely parallel to thecylindrical surface of the cylinder being engraved thereby, byadjustment of oppositely threaded shafts 168 and 170. As shown in FIGURE1, these shafts are respectively connected to meshed spur gears 172 and174, the latter of which is rotatable by wheel 176. Turning of thisWheel in one direction causes lower plate 152, and accordingly mill 82,to rotate clockwise about trunnions 158, and vice versa.

Horizontally extending through base 178, which is supported on upperplate 160, is an arm 180, as may be noted in FIGURES l and 6. This armhas associated with it a mechanism 182 (FIGURE 1) by which adjustmentcan be made to change the position of the mill axis in a horizontalplane relative to the axis of cylinder 10. That is, in the FIGURE 1view, the axle of mill 82 can be caused to be exactly in the samevertical plane as the axis of cylinder by adjusting the mill axis in ahorizontal plane utilizing adjusting wheels 184 and 186 to causepivoting movement in either of opposite angular directions about thevertical axis of base 178.

As shown in FIGURE 6, arm 180 extends both forwardly and rearwardly ofits support 178. At its rear side, it curves downwardly and is pivotedabout shaft 188, which pivot is secured in an upstanding shaft 190, thelower portion of which rests on a way or bed of frame 26, and has anintegrally downwardly extending arm member 192 including a nut securedto a feed screw 194. The downwardly extending arm 192 also connects witha forwardly protruding arm 196 that rests and slides on a front way orbed of frame 26. To this forwardly extending arm 196 is pivotallysecured a lever 198 lengthwise on which is adjustably positioned avariable weight 200. Lever 198 is coupled to the outwardly extending arm180 at the top of the mill head by a turnbuckle 202 by which thedistance between the lever and arm may be properly adjusted.

For purposes of adjusting the main bracket 56 properly in a forward anda rearward direction, use may be made of screws 204 and 206, thereby toalign chuck properly with cylinder shaft 28.

As shown in FIGURE 1, mill 82 is there disposed toward the left end ofcylinder 10. As previously indicated, it is desirable to side set orstep this mill one circumferential strip at a time during the engravingof the complete face or axial length of the desired cylindrical surfacepattern area of cylinder 10. Use may be made of two differentregistration systems to effect this function, one of these being theconically pointed, protruding registration pins 208, 210 and 212 (FIGURE4) shown on mill 82 at its opposite peripheral ends inside of thepattern area 214 in which the desired design is engraved in relief. Pins208 and 210 are circumferentially disposed and are utilized to aidaccurate registration in a circumferential direction when the mill isstepped from one strip to the next contiguous one on cylinder 10. On theother hand, registration pin 212, which is preferably in linehorizontally with pin 208 is employed to aid accurate registration in anaxial direction whenever the mill is side stepped one strip; that is, inside stepping, pin 208 is disposed in the indentation made by pin 212during the preceding circumferential strip.

The other registration system, which generally may not be as accurate asthat effected by pins 208, 210 and 212, but which is mainly utilized fora coarse adjustment, involves feed screw 194. This feed screw issupported in bearings 214 (FIGURE 1) and extends at one end to besecured as by key 216 (FIGURE 6) to a large spur gear 218. This gear inturn meshes with pinion 220 which is rotatively fixed to an intermediatesize spur gear 222. These latter two gears are disposed on a shaft whichmay be adjustable in position to accommodate different size gears, bysupporting lever 224, which in turn is adjustably secured in the slottedadjustment bracket 226. For purposes of indexing mill 82 longitudinallyof cylinder 10, a spring biased keeper or marker 228 may be secured tobracket 226 for engaging the teeth of gear 222. Rotation of this gearcauses feed screw 194 to rotate, thereby moving nut 192 and accordinglythe complete mill and head mechanism, lengthwise of cylinder 10, ineither direction, according to the direction of rotation of gear 222.Correspondence of the number of teeth passing by finger 228 perrevolution of gear 222 to the length of movement of mill 82 may bepredetermined so that the mill can be side stepped without any problemsof indexing.

In order to effect side stepping at all, it is necessary to raise mill82 off the surface of cylinder 10. This can be readily effected bylifting the outer end of lever 198, thereby raising turnbuckle 202 andpivoting arm about shaft 188, bringing head 178 and mill 82 up off thesurface of cylinder 10. Since mill 82 is coupled, however, to shafts 76and 72, the latter of which is slidable along the keys in key retainer76 and through the sleeve and housing 82, there must be some give in avertical direction to the shaft coupling. This, in certaincircumstances, may be efficiently effected by the resiliency of shaft 72itself, thereby eliminating any need for a flexible coupling 74, inwhich case shaft 72 would be itself secured directly to the upper spurgear 77 as is shown for shaft 76. However, according to the degree offlexibility desired as well as the type of material from which shaft 72is preferably made, it may be desirable to use flexible coupling 74.Since it may be necessary to be able to raise mill 82 at any point inits arcuate movement without losing the angular relation that thenexists between the mill and cylinder, coupling 74 must be flexible inall directions without shafts 72 and 76 being rotatable one relative tothe other. Any desired flexible coupling of this nature may be employed,and for exemplary purposes reference may be had to the couplingsdescribed relative to FIGURES 54 to 57 on pages 895 and 896 ofMechanical Engineers Handbook by Lional S. Marks (Fifth edition, Fourthprinting, 1954), McGraw-Hill Book Company.

With the novel apparatus thus described, a method of this invention maybe set forth in detail making reference to the apparatus as it isemployed when necessary to effect certain steps of the method. It willbe recalled that the primary object of this invention is to holdtheposition of the mill relative to the cylinder being engraved thereby,with positive'traction and consistent registration, even if the cylinderis exceptionally hard, or the pattern quite shallow. As previouslyindicated, by this invention it is possible to fully harden cylinder 10:before it is engraved by the mill, yet no slippage between the mill andthe cylinder is to be expected since the mill is positively driven viagearing in response to rotation of the cylinder itself.

As a first step, after cylinder 10 is disposed in its pillow blocks 14and properly chucked at both ends, mill 82 is caused to be disposedadjacent one end of cylinder 10. This may be accomplished by liftinglever 198 of FIGURE 6 while gear 222 is rotated until suchtime as mill82 is at the desired end peripheral strip of cylinder 10, for example asshown in FIGURE 1.

Then, an acid etching resist, for example, an asphalt base wax as Wellknown in the art, is applied on the section of cylinder 10 justunderlying the mill. After this is done, a relatively light Weight 200is placed on lever 198 so that the pressure of the mill on the resist iscan respondingly light. Cylinder 10 is then rotated, and via shaft 28,chuck 30, gears 64, 68, '70, shafts 72 and 76 with flexible coupling 74,and gears 77 and 79, mill 82 is positively rotated under pressureagainst the resist underlying it on the cylinder. When the cylinder hasmade one revolution, rotation thereof is stopped, and a close inspectionis made of the cylinder to make' sure that no doubles exist and that themarks made in the resist by the conically pointed pins 208, 210 and 212on the mill are sharp and well defined. As soon as this is all fullyassured, a heavier weight 200 is applied to lever 198 and the cylinderis rotated one or more revolutions with the mill operating into theresist under the greater pressure. As the mill turns, any resistgathered thereon is continually wiped olf. The furthest protruding partsof the registration pins and relief design on the mill remove the resistand expose areas of metal on the cylinder clearly and in a well definedmanner. When this is accomplished, lever 198 is lifted to raise the millabove the coated cylinder surface, and the mill is then side stepped, byrotation of gear 222, one circumferential strip, making sure that themill registration pins are properly interaligned with their impressionin the previous strip. The cylinder and mill are again rotated with thesame amount of pressure between them during the engraving of the secondcircumferential strip, the inspection and resist wiping stepsabove-mentioned being effected during the engraving of this strip also.

Successive circumferential strips of cylinder 10 are engraved by themill in a like manner, until the desired full 8 axial pattern length onthe cylinder face is so engraved. Then, a trough (not shown) or thelike, which is filled with a metal etching liquid such as a combinationof nitric and acetic acids, is disposed underneath cylinder 10 and thecylinder rotated therein to effect an etching of the exposed metal areasin the cylindrical surface thereof to a depth desired for the firstetching step. If this depth is not suflicient for the desired pattern,then the cylinder is engraved across its complete face, step,

by step, with mill 82 again, in the same manner as above discussed, butunder heavier contact pressure so as to allow a second etching in anacid bath to effect a greater design depth.

When the cylinder is completely engraved, its pattern is in recesswhereby the cylinder is a female embossing roll. Though designs can beembossed by the use of just the female embossing roll, it is generallymore preferable to emboss from both sides using mated embossing rolls. Amale embossing roll may be made from the female embossing roll in thesame manner as fully described in the Sunderhauf et al. Patent2,662,002, and it will be appreciated that the male embossing roll, likethe female embossing roll made in accordance with this invention, isalso pre-hardened to substantially full depth, or to any desired depth,in the same degree and manner. as for the female roll.

Theoretically, there is no need of any contact pressure between the milland resist coated cylinder since the mill is positively driven, but inpractice it is preferred to use some amount of weight 200. The amount ofweight utilized, however, is nominal, and much, much less than the hugepressures heretofore required, for example as required with theabove-mentioned Sunderhauf et al. apparatus. The invention eliminatesany need for huge registration pressures while at the same timepreventing any possible slippage between the mill and cylinder butmaintaining full traction and consistent registration at all timesduring the engraving of the full cylinder face one circumferential stripafter another.

It is therefore apparent that there has been provided.

by this invention an apparatus which accomplishes all of the objects,features, and advantages herein mentioned. It will be apparent, however,to those of ordinary skill in the art, after reading this disclosure,that other objects, features, advantages, and different embodiments ofthe invention may be effected, but it will be appreciated that theforegoing description is not intended to be limitative but onlyexemplary, the invention being defined by the appended claims. a

I claim:

1. Apparatus for making a first cylinder into an embossing roll byengraving that cylinder with a second cylinder of axial pattern lengthan integral number of times less than the desired axial pattern lengthfor the first cylinder, comprising:

means for rotatively supporting said first cylinder,

means for rotating said first cylinder, and

means coupled to the said first cylinder rotating means for drivingly'rotating the said second cylinder in locked synchronism with rotation ofthe first cylinder with cylinder axes parallel,

said second cylinder-- driving means including flexible shaft means forcarrying said second cylinder and for allowing separation of the axes ofsaid cylinders for disengaging the said cylinders and means for allowingduring said separation relative movement between said cylinders in anaxial direction while maintaining circumferential registration betweensaid cylinders.

2. Apparatus as in claim 1 wherein the flexible shaft means for drivingsaid second cylinder includes a flexible coupling together with a drivenshaft coupled thereto and extending parallale to the cylinder axes,

and a gear for rotating said driven shaft and thereby said secondcylinder, the means for allowing relative axial movement between saidcylinders including means for allowing such movement between said gearand shaft. 3. Apparatus as in claim 2 wherein said shaft is lengthwiseslidably keyed to said gear.

4. Apparatus for making a female embossing roll from a journalled firstcylinder of given diameter and axial face dimension, comprising:

a cylindrical mill that has a diameter which is related to the diameterof said cylinder substantially by a whole number and which has a patternin relief on its cylindrical surface,

one axial end of said pattern including a plurality of conically pointedcircumferential disposed registration pins and the other such endincluding at least one conically pointed registration pin alignedaxially with one of the said circumferential pins,

the axial length of said mill being approximately 1/ Nth the axiallength of said cylinder,

means for rotatively supporting said cylinder by its journals,

means for rotating said cylinder via one of its journals,

shaft means coupled at one end to said mill to effect rotation thereofwhen the shaft means is rotated,

gear means coupled between said shaft means and the other journal ofsaid cylinder for causing said mill to be rotated in locked synchronismwith said cylinder a whole number of times per revolution of saidcylinder,

said gear and shaft means being relatively slidable so that the shaftmeans can be moved axially the length of the desired pattern area on thecylinder, means in said shaft means adjacent said one end thereof forallowing flexibility of said shaft means so that said mill can beseparated from the cylinder without possibility of changing or loosingany of the relative angular relationships between the gear means, shaftmeans, mill and cylinder,

means for so separating said mill and cylinder a predetermined amount,

and means for axially moving said mill said 1/Nth distance parallel tothe cylinder axis while the mill and cylinder are so separated duringwhich time said shaft means moves relative to said gear means in thesame direction.

5. Apparatus as in claim 4 wherein said shaft means includes a shafthaving a spline from near said flexibility allowing means to the otherend of said shaft, there being a biased key fixed to rotate with saidgear means and slidably coupled to said spline.

References Cited by the Examiner UNITED STATES PATENTS 250,209 11/1881Crane 72 s5 398,243 2/ 1889 Ferguson 72-85 2,661,526 12/1953 Bruegger72--84 2,662,002 12/ 1953 Sunderhauf 76-107 FOREIGN PATENTS 203,165 10/1908 Germany.

CHARLES W. LANHAM, Primary Examiner.

H. D. HOINKES, Assistant Examiner.

1. APPARATUS FOR MAKING A FIRST CYLINDER INTO AN EMBOSSING ROLL BYENGRAVING THAT CYLINDER WITH A SECOND CYLINDER OF AXIAL PATTERN LENGTHAN INTEGRAL NUMBER OF TIMES LESS THAN THE DESIRED AXIAL PATTERN LENGTHFOR THE FIRST CYLINDER, COMPRISING: MEANS FOR ROTATIVELY SUPPORTING SAIDFIRST CYLINDER, MEANS FOR ROTATING SAID FIRST CYLINDER, AND MEANSCOUPLED TO THE SAID FIRST CYLINDER ROTATING MEANS FOR DRIVINGLY ROTATINGTHE SAID SECOND CYLINDER IN LOCKED SYNCHRONISM WITH ROTATION OF THEFIRST CYLINDER WITH CYLINDER AXES PARALLEL,